Perhaps it's the indelible "cool" factor of having a weapon that long has been a dear dream of the science fiction agency. Perhaps it's practical considerations like range and time to target impact. But for whatever the reasons, the U.S. armed forces and its contractors remain dogged in their pursuit of real-life laser weapons.

I. Projectile-Equipped Auto-Turrets Pave the Way For Laser Defenses

The current line of thought is to use lasers onboard sea ships and on armored vehicles as automated turrets capable of creating a shield against incoming hostile projectiles. While ineffective against solid slugs, high powered lasers could successfully detonate more-destructive explosion ordinances -- rockets, mortars, and explosive shells.

Col. Pete Newell, the head of the Army’s Rapid Equipping Force, says that such systems are crucial for defending locations like small outposts in the mountains of Afghanistan from deadly rocket and mortar fire, which are often directed over rocky outcroppings. States Col. Newell, "No radar can find that."

For now, the Army is looking to field defensive auto-turrets to target such projectiles. Key to that effort is the Counter-Rocket and Mortar (C-RAM) Land-based Phalanx Weapon System (LPWS). Developed primarily by the U.S. Navy, but also fielded on land, the C-RAM system has been relatively effective, considering that it's not far from being a glorified tech demo.

While the C-RAM's "kill sheet" is relatively small -- 170 mortar and rocket attacks in the battlefield since 2005 -- the Navy says it has proved equally valuable for its early detection capabilities, helping warn of over 2,000 attacks in Iraq and Afghanistan in the last seven years.

The life-saving system is hauled on a trailer. Precise details are scarce, but it is known to be a scaled down version of the Navy's Phalanx Close-in Weapon System (CIWS). The sea-based Phalanx CIWS packs a 20mm M61A1 Gatling gun capable of firing between 3,000 to 4,500 high-explosive self-destruct rounds per minute at incoming enemy munitions.

II. More Turrets Incoming

Top defense contractor, Northrop Grumman Corp. (NOC), in February scored a $132M USD contract to install and sustain several of the LPWS units at bases in Iraq and Afghanistan.

The lead designer of the sea-based CIWS, Raytheon Comp. (RTN) (which acquired the project as part of its recent acquisition of General Dynamics), has also scored an estimated $78.3M USD contract to develop the LPWS/CIWS successor, dubbed the Accelerated Improve Intercept Initiative (AI3).

Steve Bennett, project leader for the AI3 says it will be "saving soldiers' lives by 2015." He comments that the refined anti-projectile system will leverage "technologies from the Sidewinder, Avenger and Small Diameter Bomb II programs as well as leveraging program and IR&D efforts from our key suppliers."

III. Multiple Laser Solutions Vie for Land, Air, and Sea Supremacy

But what about the lasers?

Many commanders remain hopeful that lasers will be a crucial part of future campaigns, as do defense contractors like Raytheon and Northrop Grumman.

In the air realm The Boeing Comp. (BA) is showing off its advanced YAL-1 Airborne Laser (ABL) system [1][2], a system designed to ward off enemy rockets and even potentially shoot down incoming ballistic (nuclear) missiles. The chemical laser system has been in the works since 1980s, which could be seen as either a source of optimism given the long string of improvements or pessimism given that it's still not fully battle ready three decades later.

Boeing's ABL has been stuck for three decades in development purgatory. [Image Source: Boeing]

Boeing has also showed off a second design, geared towards gunship use, dubbed the Advanced Tactical Laser (ATL). Packed aboard a Hercules C-130H gunship, Boeing is targeting a power of 100 to 300 kW laser with up to 100 shots. It hit a stationary Humvee in 2009 tests, burning a hole in its front hood. The status of the project is unclear, with little news since that high profile success.

Raytheon is working on a rival system. It has paired the aforementioned Phalanx's artificial intelligence with a battery of six 32 kilowatt lasers to form the Laser Weapon System (LaWS), which shot down four unmanned aerial vehicles in 2010 testing.

IV. HEL MD Looks to Give Enemies Land Projectiles Hell

The latest efforts in laser weapons have been to bring a laser-endowed auto-turret system onto land. Boeing is working on a contract with the Army’s Space & Missile Defense Command to produce the High Energy Laser Mobile Demonstrator (HEL MD). A prototype unit was successfully integrated onboard a Oshkosh HEMTT A4 vehicle last summer and underwent low-power testing in the fall and winter.

Boeing is developing laser war-wagons. [Image Source: Boeing]

Assuming the Army bites on a follow-on contract, Boeing will next engage in field testing in 2013. Blaine Beardsley, HEL MD program manager at Boeing, spoke to Defense News about the program.

He emphasized its virtually-unlimited "magazine" and early succes in tracking targets, remarking "[The system was] very successful in acquiring and tracking the object and putting the beam on it. [Y]ou can drive it out to any location and emplace it quickly and be able to set it up with full 360-degree coverage. Even while you're utilizing the magazine and engaging targets, you’re charging that magazine."

The new system's test targets included 60 mm and 120 mm rounds.

V. Laser Weapons -- Wither Art Thou?

It's reasonable to take such claims with a degree of skepticism, or even pessimism, given that laser weapons have been a regular promise since the 1980s.

But the advent of high-power solid-state lasers -- a recent development, may prove the salvation of the promising future-weapon. Unlike gas lasers, which often require toxic chemicals and costly-charges, the solid state laser offers a virtually unlimited number of shots, as long as you can keep it powered and cooled.

Mark Gunzinger, a senior fellow at the Center for Strategic and Budgetary Assessments, says lasers have the advantage of instant kills -- crucial for anti-ordinance systems. He remarks, "You don’t have to wait for a kinetic weapon to fly to a target — it goes at the speed of light."

But even if the state of the art can be advanced to the point of having limitless shots and reliable target striking, traditional projectile weapons will still be needed, he argues, "Directed energy weapons can't completely replace kinetic defenses. They’re complementary. You need both of them because lasers have limitations in bad weather and so forth."

Ultimately the best counter to the laser -- a crucial future weapon -- may be yet another future weapon -- the rail gun. By delivering slugs at hypersonic speeds, future rail guns' ordinance may be too fast for a laser defense system to hit. And even if the laser system was fast enough to react, it would likely be unable to harm the projectile, as rail guns aim to deliver solid slugs with equivalent destructive force to explosive munitions. The laser need to be able to set off an explosive in order to "kill" an incoming round -- for now, at least.

I guess so we're veering into Startrek / Mechwarrior age, but it seems more Mechwarrior than Startrek, so maybe the next best thing we'll start seeing are: Autocannons, followed by Gauss Rifles, then most likely, 100T BattleMechs. Hopefully by then we'll have ventured into space beyond this galaxy...